Six Towers, Eight Lights Each

SMRE SUMMER 2008 CLASS PROJECTReliability of Football Field Lighting

Objective: No more than two towers may have two lights outduring an event

Sample Data1258990117311511303930133714301204709827112712771333100211178561039121879897697812339351024117011629901101933909126277593810221635119566611606091009996

Light bulb durability sample data was taken for from Fig 2.9 of Wallace R. Blischke and D.N. Prabhakar Murthy article Reliability, Modeling, Prediction and Optimization. Distribution analysis indicated a Weibull distribution was suitable for analysis

Comparison of Correlation coefficients; Weibull 0.991Lognormal 0.984Loglogistic 0.987Smallest Extreme Value 0.969Normal 0.991Logistic 0.993

15001000500

0.002

0.001

0.000

Sample Data

PD

F

15001000500

90

50

10

1

Sample Data

Perc

ent

15001000500

100

50

0

Sample Data

Perc

ent

15001000500

0.015

0.010

0.005

0.000

Sample Data

Rate

Correlation 0.991

Shape 5.96345Scale 1147.23Mean 1063.95StDev 207.329Median 1078.84IQR 280.891Failure 42Censor 0AD* 0.686

Table of StatisticsProbability Density Function

Survival Function Hazard Function

Distribution Overview Plot for Sample DataLSXY Estimates-Complete Data

Weibull

Weibull Parameters:Shape 5.96345 ()Scale 1147.23 (1/

R(t) = e -(t)

SMRE Summer 2008 Class Project

MTTF Bulb: 1064MTTF Tower: 887MTTF System: Maple Execution error

SMRE Summer 2008 Class Project

System

Tower

Bulb

Reliability Function Probability Density FunctionSystem

Max at t=825.3